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Abstract

Introduction

Standardization and validation of the color displayed by digital slides is an important
aspect of digital pathology implementation. While the most common reason for color
variation is the variance in the protocols and practices in the histology lab, the
color displayed can also be affected by variation in capture parameters (for example,
illumination and filters), image processing and display factors in the digital systems
themselves.

Method

We have been developing techniques for color validation and optimization along two
paths. The first was based on two standard slides that are scanned and displayed by
the imaging system in question. In this approach, one slide is embedded with nine
filters with colors selected especially for H&E stained slides (looking like tiny
Macbeth color chart); the specific color of the nine filters were determined in our
previous study and modified for whole slide imaging (WSI). The other slide is an H&E
stained mouse embryo. Both of these slides were scanned and the displayed images were
compared to a standard. The second approach was based on our previous multispectral
imaging research.

Discussion

As a first step, the two slide method (above) was used to identify inaccurate display
of color and its cause, and to understand the importance of accurate color in digital
pathology. We have also improved the multispectral-based algorithm for more consistent
results in stain standardization. In near future, the results of the two slide and
multispectral techniques can be combined and will be widely available.

We have been conducting a series of researches and developing projects to improve
image quality to establish Image Quality Standardization. This paper discusses one
of most important aspects of image quality – color.